- ID:
- ivo://CDS.VizieR/J/A+A/601/A83
- Title:
- GRB 140506A X-shooter spectra
- Short Name:
- J/A+A/601/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the spectroscopic and photometric late-time follow-up of the host galaxy of the long-duration Swift {gamma}-ray burst GRB140506A at z=0.889. The optical and near-infrared afterglow of this GRB had a peculiar spectral energy distribution (SED) with a strong flux-drop at 8000{AA} (4000{AA} rest-frame) suggesting an unusually steep extinction curve. By analysing the contribution and physical properties of the host galaxy, we here aim at providing additional information on the properties and origin of this steep, non-standard extinction.We find that the strong flux-drop in the GRB afterglow spectrum at <8000{AA} and rise at <4000{AA} (observers frame) is well explained by the combination of a steep extinction curve along the GRB line of sight and contamination by the host galaxy light at short wavelengths so that the scenario with an extreme 2175{AA} extinction bump can be excluded. We localise the GRB to be at a projected distance of approximately 4kpc from the centre of the host galaxy. Based on emission-line diagnostics of the four detected nebular lines, H{alpha}, H{beta}, [OII] and [OIII], we find the host to be a modestly star forming (SFR=1.34+/-0.04M_{sun}_/yr) and relatively metal poor (Z=0.35^+0:15^_0.11_Z_{sun}_) galaxy with a large dust content, characterised by a measured visual attenuation of AV=1.74+/-0.41mag. We compare the host to other GRB hosts at similar redshifts and find that it is unexceptional in all its physical properties. We model the extinction curve of the host-corrected afterglow and show that the standard dust properties causing the reddening seen in the Local Group are inadequate in describing the steep drop. We thus conclude that the steep extinction curve seen in the afterglow towards the GRB is of exotic origin and is sightline-dependent only, further confirming that this type of reddening is present only at very local scales and that it is solely a consequence of the circumburst environment.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/508/593
- Title:
- GRB 080710 bright optical/NIR afterglow
- Short Name:
- J/A+A/508/593
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the optical/near-infrared light curve of the afterglow of GRB 080710 in the context of rising afterglows. Optical and near-infrared photometry was performed using the seven-channel imager GROND and the Tautenburg Schmidt telescope. X-ray data were provided by the X-ray Telescope onboard the Swift satellite. We construct an empirical light curve model using the available broadband data, which is well-sampled in the time and frequency domains.
- ID:
- ivo://CDS.VizieR/J/ApJ/892/97
- Title:
- GRB 190114C light curves
- Short Name:
- J/ApJ/892/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report multicolor optical imaging and polarimetry observations of the afterglow of the first TeV-detected gamma-ray burst (GRB), GRB 190114C, using the RINGO3 and MASTER II polarimeters. Observations begin 31s after the onset of the GRB and continue until ~7000s postburst. The light curves reveal a chromatic break at ~400-500s, with initial temporal decay {alpha}=1.669+/-0.013 flattening to {alpha}~1 postbreak, which we model as a combination of reverse and forward shock components with magnetization parameter R_B_~70. The observed polarization degree decreases from 7.7%+/-1.1% to 2%-4% 52-109s postburst and remains steady at this level for the subsequent ~2000s at a constant position angle. Broadband spectral energy distribution modeling of the afterglow confirms that GRB 190114C is highly obscured (A_v,HG_=1.49+/-0.12mag; N_H,HG_=(9.0+/-0.03)x10^22^cm^-2^). We interpret the measured afterglow polarization as intrinsically low and dominated by dust -in contrast to the P>10% measured previously for other GRB reverse shocks-with a small contribution from polarized prompt photons in the first minute. We test whether first- and higher-order inverse Compton scattering in a magnetized reverse shock can explain the low optical polarization and subteraelectronvolt emission but conclude that neither is explained in the reverse shock inverse Compton model. Instead, the unexpectedly low intrinsic polarization degree in GRB 190114C can be explained if large-scale jet magnetic fields are distorted on timescales prior to reverse shock emission.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A39
- Title:
- GRB190114C spectra and light curves
- Short Name:
- J/A+A/659/A39
- Date:
- 01 Mar 2022 09:36:26
- Publisher:
- CDS
- Description:
- We observed GRB190114C (redshift z=0.4245), the first gamma-ray burst (GRB) ever detected at TeV energies, at optical and near-infrared wavelengths with several ground-based telescopes and the Hubble Space Telescope, with the primary goal of studying its underlying supernova, SN 2019jrj. The monitoring spanned the time interval between 1.3 and 370 days after the burst, in the observer frame. We find that the afterglow emission can be modelled with a forward shock propagating in a uniform medium modified by time-variable extinction along the line of sight. A jet break could be present after 7 rest-frame days, and accordingly the maximum luminosity of the underlying supernova (SN) ranges between that of stripped-envelope core-collapse SNe of intermediate luminosity and that of the luminous GRB-associated SN 2013dx. The observed spectral absorption lines of SN 2019jrj are not as broad as in classical GRB SNe and are instead more similar to those of less-luminous core-collapse SNe. Taking the broad-lined stripped-envelope core-collapse SN 2004aw as an analogue, we tentatively derive the basic physical properties of SN 2019jrj. We discuss the possibility that a fraction of the TeV emission of this source might have had a hadronic origin and estimate the expected high-energy neutrino detection level with IceCube.
- ID:
- ivo://CDS.VizieR/J/ApJS/169/62
- Title:
- GRB database of spectral lags
- Short Name:
- J/ApJS/169/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a database of spectral lags and internal luminosity function (ILF) measurements for gamma-ray bursts (GRBs) in the BATSE catalog. Measurements were made using 64ms count rate data and are defined for various combinations of the four broadband BATSE energy channels.
166. GRB from RICE data
- ID:
- ivo://CDS.VizieR/J/other/APh/26.367
- Title:
- GRB from RICE data
- Short Name:
- J/other/APh/26.3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present limits on ultra-high energy (UHE; E_{nu}_>10^15^eV) neutrino fluxes from gamma-ray bursts (GRBs), based on recently presented data, limits, and simulations from the RICE experiment. We use data from five recorded transients with sufficient photon spectral shape and redshift information to derive an expected neutrino flux, assuming that the observed photons are linked to neutrino production through pion decay via the well-known Waxman-Bahcall prescription. Knowing the declination of the observed burst, as well as the RICE sensitivity as a function of polar angle and the previously published non-observation of any neutrino events allows an estimate of the sensitivity to a given neutrino flux. Although several orders of magnitude weaker than the expected fluxes, our GRB neutrino flux limits are nevertheless the first in the PeVEeV energy regime. For completeness, we also provide a listing of other bursts, recorded at times when the RICE experiment was active, but requiring some assumptions regarding luminosity and redshift to permit estimates of the neutrino flux.
- ID:
- ivo://CDS.VizieR/J/ApJ/778/128
- Title:
- GRB-host galaxies photometry
- Short Name:
- J/ApJ/778/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations and analysis of the host galaxies of 23 heavily dust-obscured gamma-ray bursts (GRBs) observed by the Swift satellite during the years 2005-2009, representing all GRBs with an unambiguous host-frame extinction of A_V_>1mag from this period. Deep observations with Keck, Gemini, Very Large Telescope, Hubble Space Telescope, and Spitzer successfully detect the host galaxies and establish spectroscopic or photometric redshifts for all 23 events, enabling us to provide measurements of the intrinsic host star formation rates, stellar masses, and mean extinctions. Compared to the hosts of unobscured GRBs at similar redshifts, we find that the hosts of dust-obscured GRBs are (on average) more massive by about an order of magnitude and also more rapidly star forming and dust obscured. While this demonstrates that GRBs populate all types of star-forming galaxies, including the most massive, luminous systems at z{approx}2, at redshifts below 1.5 the overall GRB population continues to show a highly significant aversion to massive galaxies and a preference for low-mass systems relative to what would be expected given a purely star-formation-rate-selected galaxy sample. This supports the notion that the GRB rate is strongly dependent on metallicity, and may suggest that the most massive galaxies in the universe underwent a transition in their chemical properties ~9Gyr ago. We also conclude that, based on the absence of unobscured GRBs in massive galaxies and the absence of obscured GRBs in low-mass galaxies, the dust distributions of the lowest-mass and the highest-mass galaxies are relatively homogeneous, while intermediate-mass galaxies (~10^9^M_{sun}_) have diverse internal properties.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A107
- Title:
- GRB 080810 Keck/HIRES spectrum
- Short Name:
- J/A+A/607/A107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We reveal multiple components of an interacting galaxy system at z~3.35 through a detailed analysis of the exquisite high-resolution Keck/HIRES spectrum of the afterglow of a gamma-ray burst (GRB). Through Voigt-profile fitting of absorption lines from the Lyman-series, we constrain the neutral hydrogen column density to N_HI_<=10^18.35^cm^-2^ for the densest of four distinct systems at the host redshift of GRB 080810, among the lowest NHI ever observed in a GRB host, despite the line of sight passing within a projected 5kpc of the galaxy centres. By detailed analysis of the corresponding metal absorption lines, we derive chemical, ionic and kinematic properties of the individual absorbing systems, and thus build a picture of the host as a whole. Striking differences between the systems imply that the line of sight passes through several phases of gas: the star-forming regions of the GRB host; enriched material in the form of a galactic outflow; the hot and ionised halo of a second, interacting galaxy falling towards the host at a line-of-sight velocity of 700km/s; and a cool, metal-poor cloud which may represent one of the best candidates yet for the inflow of metal-poor gas from the intergalactic medium.
- ID:
- ivo://CDS.VizieR/J/ApJ/828/36
- Title:
- GRB light-curve decay indices with Swift
- Short Name:
- J/ApJ/828/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we study the distribution of temporal power-law decay indices, {alpha}, in the gamma-ray burst (GRB) afterglow phase, fitted for 176 GRBs (139 long GRBs, 12 short GRBs with extended emission, and 25 X-ray flashes) with known redshifts. These indices are compared with the temporal decay index, {alpha}_W_, derived with the light-curve fitting using the Willingale+ (2007ApJ...662.1093W) model. This model fitting yields similar distributions of {alpha}_W_ to the fitted {alpha}, but for individual bursts a difference can be significant. Analysis of ({alpha}, L_a_) distribution, where L_a_ is the characteristic luminosity at the end of the plateau, reveals only a weak correlation of these quantities. However, we discovered a significant regular trend when studying GRB {alpha} values along the Dainotti+ (2013ApJ...774..157D) correlation between L_a_ and the end time of the plateau emission in the rest frame, T_a_^*^, hereafter LT correlation. We note a systematic variation of the {alpha} parameter distribution with luminosity for any selected T_a_^*^. We analyze this systematics with respect to the fitted LT correlation line, expecting that the presented trend may allow us to constrain the GRB physical models. We also attempted to use the derived correlation of {alpha}(T_a_) versus L_a_(T_a_) to diminish the luminosity scatter related to the variations of {alpha} along the LT distribution, a step forward in the effort of standardizing GRBs. A proposed toy model accounting for this systematics applied to the analyzed GRB distribution results in a slight increase of the LT correlation coefficient.
- ID:
- ivo://CDS.VizieR/J/ApJ/672/449
- Title:
- GRB 061126 light curves
- Short Name:
- J/ApJ/672/449
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on observations of a gamma-ray burst (GRB 061126) with an extremely bright (R~12mag at peak) early-time optical afterglow. The optical afterglow is already fading as a power law 22s after the trigger, with no detectable prompt contribution in our first exposure, which was coincident with a large prompt-emission gamma-ray pulse. The optical-infrared photometric SED is an excellent fit to a power law, but it exhibits a moderate red-to-blue evolution in the spectral index at about 500s after the burst. This color change is contemporaneous with a switch from a relatively fast decay to slower decay.
